BKSB Data and Statistical Interpretation 3

Question 1

The mean of five numbers is 14. Four of the numbers are 10, 12, 16, and 18. What is the fifth number?

Accepted Answer

14

Answer

Sum = 5 × 14 = 70; known sum = 10+12+16+18 = 56; fifth number = 70 − 56 = 14.

Question 2

A dual bar chart compares male and female test results. Males averaged 72 and females averaged 68. What is the combined average if there are equal numbers of each?

Accepted Answer

70

Answer

With equal numbers, combined average = (72 + 68) ÷ 2 = 70.

Question 3

A cumulative frequency graph shows that 60 out of 100 students scored below 55 marks. What is the probability that a randomly selected student scored 55 or above?

Accepted Answer

0.4

Answer

100 − 60 = 40 students scored 55 or above, so probability = 40/100 = 0.4.

Question 4

In a data set, the lower quartile is 20 and the upper quartile is 40. What is the interquartile range (IQR)?

Accepted Answer

20

Answer

IQR = upper quartile − lower quartile = 40 − 20 = 20.

Question 5

A pictogram uses one symbol to represent 4 people. A category shows 6 full symbols and one half symbol. How many people does this represent?

Accepted Answer

26

Answer

6 full symbols = 6 × 4 = 24; half symbol = 2; total = 24 + 2 = 26.

(BKSB) Basic and Key Skills Builder Practice Test

(BKSB) Basic and Key Skills Builder Practice Test

BKSB Data and Statistical Interpretation 3